For improved availability of fuels and for using alternative fuels in gas turbines, the injection of different fuels is combined. This is brought about by means of a double fuel nozzle (dual fuel nozzle) which comprises two tubes which fit into each other. A first fuel is injected through the outer tube by means of a lobe mixer. A second fuel is added through the inner tube perpendicularly to the air flow (cross inflow). For a stable operation, the position of the lobe mixer in relation to the inner tube is vital.